16 – 19 March 2009
Climate Change of the Near Surface Wind Sped over Europe and North Atlantic in the IPCC A2
scenario
Carl von Ossietzky University Oldenburg, ForWind – Centre for Wind Energy Research
Kay Sušelj, Detlev Heinemann, Abha Sood
K. Sušelj et al / page 2
Outlook
Motivation Methodology Results – climate change of WS:
Winter Summer
Outlook and conclusions
K. Sušelj et al / page 3
Motivation
Importance of Wind Speed (WS) climate change for wind energy High sensitivity of wind power on WS
Inconsistent results of climate change of WS over Europe in recent literature (e.g. Räisänen et al., 2004; Pryor et al., 2005,2006)
Last IPCC report: Confidence in predicting future change of WS over Europe is low
K. Sušelj et al / page 4
Methodology
Statistically estimate climate change of WS over Europe and North Atlantic based on forcing parameter, i.e. Sea Level Pressure (SLP)1) Find WS patterns optimized in explaining WS trend
(past data) – Trend Empirical Orthogonal Functions2) Statistically relate the WS patterns to SLP patterns
(past data)3) Investigate change of SLP patterns in future climate4)Estimate climate change of WS
SLP from ensemble of Global Circulation Models (GCMs) - estimation of the confidence of WS change
GCM simulation based on SRES IPCC A2 scenario
K. Sušelj et al / page 5
Assumptions:
WS well defined by the large scale SLP forcing Statistical relationship between SLP and WS patterns
describes physical coupling WS patterns from past climate remain significant in
future climate Seasonally dependent WS patterns and relationship
to SLP – independent analysis for four seasons of the year
K. Sušelj et al / page 6
Trend WS pattern and related SLP patterns – Winter (Dec.-Feb.)
Sea Level Pressure Time Series
WS – red; SLP - green
K. Sušelj et al / page 7
Wind Speed change in Winter (Dec.-Feb.)
SLP data from the GCM results used for 4th IPCC report
17 GCMs with 1-5 runs
Estimation of reliability of results
K. Sušelj et al / page 8
Wind speed change in Winter (Dec.-Feb.)
90th percentile 10th percentileGCM mean
K. Sušelj et al / page 9
Similar WS and SLP patterns, moved towards North to Northwest
Lower WS trend in past climate SLP and WS relationship less clear Contribution of local WS forcing more important
Wind speed change in other seasons compared to Winter
K. Sušelj et al / page 10
Change of WS in Summer (Jun.-Aug.)
GCM mean 90th percentile 10th percentile
10m Wind Speed
K. Sušelj et al / page 11
Conclusions
Clear signal increase of WS over the North Atlantic and North Europe in Winter
The climate change of WS is small and not significant in other seasons
Analysis restricted to IPCC A2 scenario Only the GCM resolved (synoptic scale) forcing The GCMs cannot well represent the past variability of
the SLP patterns Further downscaling of wind can be done based on
the selected GCMs
